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diff --git a/lwip/src/include/lwip/priv/tcp_priv.h b/lwip/src/include/lwip/priv/tcp_priv.h
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+/**
+ * @file
+ * TCP internal implementations (do not use in application code)
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+#ifndef LWIP_HDR_TCP_PRIV_H
+#define LWIP_HDR_TCP_PRIV_H
+
+#include "lwip/opt.h"
+
+#if LWIP_TCP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/tcp.h"
+#include "lwip/mem.h"
+#include "lwip/pbuf.h"
+#include "lwip/ip.h"
+#include "lwip/icmp.h"
+#include "lwip/err.h"
+#include "lwip/ip6.h"
+#include "lwip/ip6_addr.h"
+#include "lwip/prot/tcp.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Functions for interfacing with TCP: */
+
+/* Lower layer interface to TCP: */
+void tcp_init (void); /* Initialize this module. */
+void tcp_tmr (void); /* Must be called every
+ TCP_TMR_INTERVAL
+ ms. (Typically 250 ms). */
+/* It is also possible to call these two functions at the right
+ intervals (instead of calling tcp_tmr()). */
+void tcp_slowtmr (void);
+void tcp_fasttmr (void);
+
+/* Call this from a netif driver (watch out for threading issues!) that has
+ returned a memory error on transmit and now has free buffers to send more.
+ This iterates all active pcbs that had an error and tries to call
+ tcp_output, so use this with care as it might slow down the system. */
+void tcp_txnow (void);
+
+/* Only used by IP to pass a TCP segment to TCP: */
+void tcp_input (struct pbuf *p, struct netif *inp);
+/* Used within the TCP code only: */
+struct tcp_pcb * tcp_alloc (u8_t prio);
+void tcp_free (struct tcp_pcb *pcb);
+void tcp_abandon (struct tcp_pcb *pcb, int reset);
+err_t tcp_send_empty_ack(struct tcp_pcb *pcb);
+err_t tcp_rexmit (struct tcp_pcb *pcb);
+err_t tcp_rexmit_rto_prepare(struct tcp_pcb *pcb);
+void tcp_rexmit_rto_commit(struct tcp_pcb *pcb);
+void tcp_rexmit_rto (struct tcp_pcb *pcb);
+void tcp_rexmit_fast (struct tcp_pcb *pcb);
+u32_t tcp_update_rcv_ann_wnd(struct tcp_pcb *pcb);
+err_t tcp_process_refused_data(struct tcp_pcb *pcb);
+
+/**
+ * This is the Nagle algorithm: try to combine user data to send as few TCP
+ * segments as possible. Only send if
+ * - no previously transmitted data on the connection remains unacknowledged or
+ * - the TF_NODELAY flag is set (nagle algorithm turned off for this pcb) or
+ * - the only unsent segment is at least pcb->mss bytes long (or there is more
+ * than one unsent segment - with lwIP, this can happen although unsent->len < mss)
+ * - or if we are in fast-retransmit (TF_INFR)
+ */
+#define tcp_do_output_nagle(tpcb) ((((tpcb)->unacked == NULL) || \
+ ((tpcb)->flags & (TF_NODELAY | TF_INFR)) || \
+ (((tpcb)->unsent != NULL) && (((tpcb)->unsent->next != NULL) || \
+ ((tpcb)->unsent->len >= (tpcb)->mss))) || \
+ ((tcp_sndbuf(tpcb) == 0) || (tcp_sndqueuelen(tpcb) >= TCP_SND_QUEUELEN)) \
+ ) ? 1 : 0)
+#define tcp_output_nagle(tpcb) (tcp_do_output_nagle(tpcb) ? tcp_output(tpcb) : ERR_OK)
+
+
+#define TCP_SEQ_LT(a,b) ((s32_t)((u32_t)(a) - (u32_t)(b)) < 0)
+#define TCP_SEQ_LEQ(a,b) ((s32_t)((u32_t)(a) - (u32_t)(b)) <= 0)
+#define TCP_SEQ_GT(a,b) ((s32_t)((u32_t)(a) - (u32_t)(b)) > 0)
+#define TCP_SEQ_GEQ(a,b) ((s32_t)((u32_t)(a) - (u32_t)(b)) >= 0)
+/* is b<=a<=c? */
+#if 0 /* see bug #10548 */
+#define TCP_SEQ_BETWEEN(a,b,c) ((c)-(b) >= (a)-(b))
+#endif
+#define TCP_SEQ_BETWEEN(a,b,c) (TCP_SEQ_GEQ(a,b) && TCP_SEQ_LEQ(a,c))
+
+#ifndef TCP_TMR_INTERVAL
+#define TCP_TMR_INTERVAL 250 /* The TCP timer interval in milliseconds. */
+#endif /* TCP_TMR_INTERVAL */
+
+#ifndef TCP_FAST_INTERVAL
+#define TCP_FAST_INTERVAL TCP_TMR_INTERVAL /* the fine grained timeout in milliseconds */
+#endif /* TCP_FAST_INTERVAL */
+
+#ifndef TCP_SLOW_INTERVAL
+#define TCP_SLOW_INTERVAL (2*TCP_TMR_INTERVAL) /* the coarse grained timeout in milliseconds */
+#endif /* TCP_SLOW_INTERVAL */
+
+#define TCP_FIN_WAIT_TIMEOUT 20000 /* milliseconds */
+#define TCP_SYN_RCVD_TIMEOUT 20000 /* milliseconds */
+
+#define TCP_OOSEQ_TIMEOUT 6U /* x RTO */
+
+#ifndef TCP_MSL
+#define TCP_MSL 60000UL /* The maximum segment lifetime in milliseconds */
+#endif
+
+/* Keepalive values, compliant with RFC 1122. Don't change this unless you know what you're doing */
+#ifndef TCP_KEEPIDLE_DEFAULT
+#define TCP_KEEPIDLE_DEFAULT 7200000UL /* Default KEEPALIVE timer in milliseconds */
+#endif
+
+#ifndef TCP_KEEPINTVL_DEFAULT
+#define TCP_KEEPINTVL_DEFAULT 75000UL /* Default Time between KEEPALIVE probes in milliseconds */
+#endif
+
+#ifndef TCP_KEEPCNT_DEFAULT
+#define TCP_KEEPCNT_DEFAULT 9U /* Default Counter for KEEPALIVE probes */
+#endif
+
+#define TCP_MAXIDLE TCP_KEEPCNT_DEFAULT * TCP_KEEPINTVL_DEFAULT /* Maximum KEEPALIVE probe time */
+
+#define TCP_TCPLEN(seg) ((seg)->len + (((TCPH_FLAGS((seg)->tcphdr) & (TCP_FIN | TCP_SYN)) != 0) ? 1U : 0U))
+
+/** Flags used on input processing, not on pcb->flags
+*/
+#define TF_RESET (u8_t)0x08U /* Connection was reset. */
+#define TF_CLOSED (u8_t)0x10U /* Connection was successfully closed. */
+#define TF_GOT_FIN (u8_t)0x20U /* Connection was closed by the remote end. */
+
+
+#if LWIP_EVENT_API
+
+#define TCP_EVENT_ACCEPT(lpcb,pcb,arg,err,ret) ret = lwip_tcp_event(arg, (pcb),\
+ LWIP_EVENT_ACCEPT, NULL, 0, err)
+#define TCP_EVENT_SENT(pcb,space,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
+ LWIP_EVENT_SENT, NULL, space, ERR_OK)
+#define TCP_EVENT_RECV(pcb,p,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
+ LWIP_EVENT_RECV, (p), 0, (err))
+#define TCP_EVENT_CLOSED(pcb,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
+ LWIP_EVENT_RECV, NULL, 0, ERR_OK)
+#define TCP_EVENT_CONNECTED(pcb,err,ret) ret = lwip_tcp_event((pcb)->callback_arg, (pcb),\
+ LWIP_EVENT_CONNECTED, NULL, 0, (err))
+#define TCP_EVENT_POLL(pcb,ret) do { if ((pcb)->state != SYN_RCVD) { \
+ ret = lwip_tcp_event((pcb)->callback_arg, (pcb), LWIP_EVENT_POLL, NULL, 0, ERR_OK); \
+ } else { \
+ ret = ERR_ARG; } } while(0)
+/* For event API, last state SYN_RCVD must be excluded here: the application
+ has not seen this pcb, yet! */
+#define TCP_EVENT_ERR(last_state,errf,arg,err) do { if (last_state != SYN_RCVD) { \
+ lwip_tcp_event((arg), NULL, LWIP_EVENT_ERR, NULL, 0, (err)); } } while(0)
+
+#else /* LWIP_EVENT_API */
+
+#define TCP_EVENT_ACCEPT(lpcb,pcb,arg,err,ret) \
+ do { \
+ if((lpcb)->accept != NULL) \
+ (ret) = (lpcb)->accept((arg),(pcb),(err)); \
+ else (ret) = ERR_ARG; \
+ } while (0)
+
+#define TCP_EVENT_SENT(pcb,space,ret) \
+ do { \
+ if((pcb)->sent != NULL) \
+ (ret) = (pcb)->sent((pcb)->callback_arg,(pcb),(space)); \
+ else (ret) = ERR_OK; \
+ } while (0)
+
+#define TCP_EVENT_RECV(pcb,p,err,ret) \
+ do { \
+ if((pcb)->recv != NULL) { \
+ (ret) = (pcb)->recv((pcb)->callback_arg,(pcb),(p),(err));\
+ } else { \
+ (ret) = tcp_recv_null(NULL, (pcb), (p), (err)); \
+ } \
+ } while (0)
+
+#define TCP_EVENT_CLOSED(pcb,ret) \
+ do { \
+ if(((pcb)->recv != NULL)) { \
+ (ret) = (pcb)->recv((pcb)->callback_arg,(pcb),NULL,ERR_OK);\
+ } else { \
+ (ret) = ERR_OK; \
+ } \
+ } while (0)
+
+#define TCP_EVENT_CONNECTED(pcb,err,ret) \
+ do { \
+ if((pcb)->connected != NULL) \
+ (ret) = (pcb)->connected((pcb)->callback_arg,(pcb),(err)); \
+ else (ret) = ERR_OK; \
+ } while (0)
+
+#define TCP_EVENT_POLL(pcb,ret) \
+ do { \
+ if((pcb)->poll != NULL) \
+ (ret) = (pcb)->poll((pcb)->callback_arg,(pcb)); \
+ else (ret) = ERR_OK; \
+ } while (0)
+
+#define TCP_EVENT_ERR(last_state,errf,arg,err) \
+ do { \
+ LWIP_UNUSED_ARG(last_state); \
+ if((errf) != NULL) \
+ (errf)((arg),(err)); \
+ } while (0)
+
+#endif /* LWIP_EVENT_API */
+
+/** Enabled extra-check for TCP_OVERSIZE if LWIP_DEBUG is enabled */
+#if TCP_OVERSIZE && defined(LWIP_DEBUG)
+#define TCP_OVERSIZE_DBGCHECK 1
+#else
+#define TCP_OVERSIZE_DBGCHECK 0
+#endif
+
+/** Don't generate checksum on copy if CHECKSUM_GEN_TCP is disabled */
+#define TCP_CHECKSUM_ON_COPY (LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_TCP)
+
+/* This structure represents a TCP segment on the unsent, unacked and ooseq queues */
+struct tcp_seg {
+ struct tcp_seg *next; /* used when putting segments on a queue */
+ struct pbuf *p; /* buffer containing data + TCP header */
+ u16_t len; /* the TCP length of this segment */
+#if TCP_OVERSIZE_DBGCHECK
+ u16_t oversize_left; /* Extra bytes available at the end of the last
+ pbuf in unsent (used for asserting vs.
+ tcp_pcb.unsent_oversize only) */
+#endif /* TCP_OVERSIZE_DBGCHECK */
+#if TCP_CHECKSUM_ON_COPY
+ u16_t chksum;
+ u8_t chksum_swapped;
+#endif /* TCP_CHECKSUM_ON_COPY */
+ u8_t flags;
+#define TF_SEG_OPTS_MSS (u8_t)0x01U /* Include MSS option (only used in SYN segments) */
+#define TF_SEG_OPTS_TS (u8_t)0x02U /* Include timestamp option. */
+#define TF_SEG_DATA_CHECKSUMMED (u8_t)0x04U /* ALL data (not the header) is
+ checksummed into 'chksum' */
+#define TF_SEG_OPTS_WND_SCALE (u8_t)0x08U /* Include WND SCALE option (only used in SYN segments) */
+#define TF_SEG_OPTS_SACK_PERM (u8_t)0x10U /* Include SACK Permitted option (only used in SYN segments) */
+ struct tcp_hdr *tcphdr; /* the TCP header */
+};
+
+#define LWIP_TCP_OPT_EOL 0
+#define LWIP_TCP_OPT_NOP 1
+#define LWIP_TCP_OPT_MSS 2
+#define LWIP_TCP_OPT_WS 3
+#define LWIP_TCP_OPT_SACK_PERM 4
+#define LWIP_TCP_OPT_TS 8
+
+#define LWIP_TCP_OPT_LEN_MSS 4
+#if LWIP_TCP_TIMESTAMPS
+#define LWIP_TCP_OPT_LEN_TS 10
+#define LWIP_TCP_OPT_LEN_TS_OUT 12 /* aligned for output (includes NOP padding) */
+#else
+#define LWIP_TCP_OPT_LEN_TS_OUT 0
+#endif
+#if LWIP_WND_SCALE
+#define LWIP_TCP_OPT_LEN_WS 3
+#define LWIP_TCP_OPT_LEN_WS_OUT 4 /* aligned for output (includes NOP padding) */
+#else
+#define LWIP_TCP_OPT_LEN_WS_OUT 0
+#endif
+
+#if LWIP_TCP_SACK_OUT
+#define LWIP_TCP_OPT_LEN_SACK_PERM 2
+#define LWIP_TCP_OPT_LEN_SACK_PERM_OUT 4 /* aligned for output (includes NOP padding) */
+#else
+#define LWIP_TCP_OPT_LEN_SACK_PERM_OUT 0
+#endif
+
+#define LWIP_TCP_OPT_LENGTH(flags) \
+ ((flags) & TF_SEG_OPTS_MSS ? LWIP_TCP_OPT_LEN_MSS : 0) + \
+ ((flags) & TF_SEG_OPTS_TS ? LWIP_TCP_OPT_LEN_TS_OUT : 0) + \
+ ((flags) & TF_SEG_OPTS_WND_SCALE ? LWIP_TCP_OPT_LEN_WS_OUT : 0) + \
+ ((flags) & TF_SEG_OPTS_SACK_PERM ? LWIP_TCP_OPT_LEN_SACK_PERM_OUT : 0)
+
+/** This returns a TCP header option for MSS in an u32_t */
+#define TCP_BUILD_MSS_OPTION(mss) lwip_htonl(0x02040000 | ((mss) & 0xFFFF))
+
+#if LWIP_WND_SCALE
+#define TCPWNDSIZE_F U32_F
+#define TCPWND_MAX 0xFFFFFFFFU
+#define TCPWND_CHECK16(x) LWIP_ASSERT("window size > 0xFFFF", (x) <= 0xFFFF)
+#define TCPWND_MIN16(x) ((u16_t)LWIP_MIN((x), 0xFFFF))
+#else /* LWIP_WND_SCALE */
+#define TCPWNDSIZE_F U16_F
+#define TCPWND_MAX 0xFFFFU
+#define TCPWND_CHECK16(x)
+#define TCPWND_MIN16(x) x
+#endif /* LWIP_WND_SCALE */
+
+/* Global variables: */
+extern struct tcp_pcb *tcp_input_pcb;
+extern u32_t tcp_ticks;
+extern u8_t tcp_active_pcbs_changed;
+
+/* The TCP PCB lists. */
+union tcp_listen_pcbs_t { /* List of all TCP PCBs in LISTEN state. */
+ struct tcp_pcb_listen *listen_pcbs;
+ struct tcp_pcb *pcbs;
+};
+extern struct tcp_pcb *tcp_bound_pcbs;
+extern union tcp_listen_pcbs_t tcp_listen_pcbs;
+extern struct tcp_pcb *tcp_active_pcbs; /* List of all TCP PCBs that are in a
+ state in which they accept or send
+ data. */
+extern struct tcp_pcb *tcp_tw_pcbs; /* List of all TCP PCBs in TIME-WAIT. */
+
+#define NUM_TCP_PCB_LISTS_NO_TIME_WAIT 3
+#define NUM_TCP_PCB_LISTS 4
+extern struct tcp_pcb ** const tcp_pcb_lists[NUM_TCP_PCB_LISTS];
+
+/* Axioms about the above lists:
+ 1) Every TCP PCB that is not CLOSED is in one of the lists.
+ 2) A PCB is only in one of the lists.
+ 3) All PCBs in the tcp_listen_pcbs list is in LISTEN state.
+ 4) All PCBs in the tcp_tw_pcbs list is in TIME-WAIT state.
+*/
+/* Define two macros, TCP_REG and TCP_RMV that registers a TCP PCB
+ with a PCB list or removes a PCB from a list, respectively. */
+#ifndef TCP_DEBUG_PCB_LISTS
+#define TCP_DEBUG_PCB_LISTS 0
+#endif
+#if TCP_DEBUG_PCB_LISTS
+#define TCP_REG(pcbs, npcb) do {\
+ struct tcp_pcb *tcp_tmp_pcb; \
+ LWIP_DEBUGF(TCP_DEBUG, ("TCP_REG %p local port %"U16_F"\n", (void *)(npcb), (npcb)->local_port)); \
+ for (tcp_tmp_pcb = *(pcbs); \
+ tcp_tmp_pcb != NULL; \
+ tcp_tmp_pcb = tcp_tmp_pcb->next) { \
+ LWIP_ASSERT("TCP_REG: already registered\n", tcp_tmp_pcb != (npcb)); \
+ } \
+ LWIP_ASSERT("TCP_REG: pcb->state != CLOSED", ((pcbs) == &tcp_bound_pcbs) || ((npcb)->state != CLOSED)); \
+ (npcb)->next = *(pcbs); \
+ LWIP_ASSERT("TCP_REG: npcb->next != npcb", (npcb)->next != (npcb)); \
+ *(pcbs) = (npcb); \
+ LWIP_ASSERT("TCP_REG: tcp_pcbs sane", tcp_pcbs_sane()); \
+ tcp_timer_needed(); \
+ } while(0)
+#define TCP_RMV(pcbs, npcb) do { \
+ struct tcp_pcb *tcp_tmp_pcb; \
+ LWIP_ASSERT("TCP_RMV: pcbs != NULL", *(pcbs) != NULL); \
+ LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removing %p from %p\n", (void *)(npcb), (void *)(*(pcbs)))); \
+ if(*(pcbs) == (npcb)) { \
+ *(pcbs) = (*pcbs)->next; \
+ } else for (tcp_tmp_pcb = *(pcbs); tcp_tmp_pcb != NULL; tcp_tmp_pcb = tcp_tmp_pcb->next) { \
+ if(tcp_tmp_pcb->next == (npcb)) { \
+ tcp_tmp_pcb->next = (npcb)->next; \
+ break; \
+ } \
+ } \
+ (npcb)->next = NULL; \
+ LWIP_ASSERT("TCP_RMV: tcp_pcbs sane", tcp_pcbs_sane()); \
+ LWIP_DEBUGF(TCP_DEBUG, ("TCP_RMV: removed %p from %p\n", (void *)(npcb), (void *)(*(pcbs)))); \
+ } while(0)
+
+#else /* LWIP_DEBUG */
+
+#define TCP_REG(pcbs, npcb) \
+ do { \
+ (npcb)->next = *pcbs; \
+ *(pcbs) = (npcb); \
+ tcp_timer_needed(); \
+ } while (0)
+
+#define TCP_RMV(pcbs, npcb) \
+ do { \
+ if(*(pcbs) == (npcb)) { \
+ (*(pcbs)) = (*pcbs)->next; \
+ } \
+ else { \
+ struct tcp_pcb *tcp_tmp_pcb; \
+ for (tcp_tmp_pcb = *pcbs; \
+ tcp_tmp_pcb != NULL; \
+ tcp_tmp_pcb = tcp_tmp_pcb->next) { \
+ if(tcp_tmp_pcb->next == (npcb)) { \
+ tcp_tmp_pcb->next = (npcb)->next; \
+ break; \
+ } \
+ } \
+ } \
+ (npcb)->next = NULL; \
+ } while(0)
+
+#endif /* LWIP_DEBUG */
+
+#define TCP_REG_ACTIVE(npcb) \
+ do { \
+ TCP_REG(&tcp_active_pcbs, npcb); \
+ tcp_active_pcbs_changed = 1; \
+ } while (0)
+
+#define TCP_RMV_ACTIVE(npcb) \
+ do { \
+ TCP_RMV(&tcp_active_pcbs, npcb); \
+ tcp_active_pcbs_changed = 1; \
+ } while (0)
+
+#define TCP_PCB_REMOVE_ACTIVE(pcb) \
+ do { \
+ tcp_pcb_remove(&tcp_active_pcbs, pcb); \
+ tcp_active_pcbs_changed = 1; \
+ } while (0)
+
+
+/* Internal functions: */
+struct tcp_pcb *tcp_pcb_copy(struct tcp_pcb *pcb);
+void tcp_pcb_purge(struct tcp_pcb *pcb);
+void tcp_pcb_remove(struct tcp_pcb **pcblist, struct tcp_pcb *pcb);
+
+void tcp_segs_free(struct tcp_seg *seg);
+void tcp_seg_free(struct tcp_seg *seg);
+struct tcp_seg *tcp_seg_copy(struct tcp_seg *seg);
+
+#define tcp_ack(pcb) \
+ do { \
+ if((pcb)->flags & TF_ACK_DELAY) { \
+ tcp_clear_flags(pcb, TF_ACK_DELAY); \
+ tcp_ack_now(pcb); \
+ } \
+ else { \
+ tcp_set_flags(pcb, TF_ACK_DELAY); \
+ } \
+ } while (0)
+
+#define tcp_ack_now(pcb) \
+ tcp_set_flags(pcb, TF_ACK_NOW)
+
+err_t tcp_send_fin(struct tcp_pcb *pcb);
+err_t tcp_enqueue_flags(struct tcp_pcb *pcb, u8_t flags);
+
+void tcp_rexmit_seg(struct tcp_pcb *pcb, struct tcp_seg *seg);
+
+void tcp_rst(const struct tcp_pcb* pcb, u32_t seqno, u32_t ackno,
+ const ip_addr_t *local_ip, const ip_addr_t *remote_ip,
+ u16_t local_port, u16_t remote_port);
+
+u32_t tcp_next_iss(struct tcp_pcb *pcb);
+
+err_t tcp_keepalive(struct tcp_pcb *pcb);
+err_t tcp_split_unsent_seg(struct tcp_pcb *pcb, u16_t split);
+err_t tcp_zero_window_probe(struct tcp_pcb *pcb);
+void tcp_trigger_input_pcb_close(void);
+
+#if TCP_CALCULATE_EFF_SEND_MSS
+u16_t tcp_eff_send_mss_netif(u16_t sendmss, struct netif *outif,
+ const ip_addr_t *dest);
+#define tcp_eff_send_mss(sendmss, src, dest) \
+ tcp_eff_send_mss_netif(sendmss, ip_route(src, dest), dest)
+#endif /* TCP_CALCULATE_EFF_SEND_MSS */
+
+#if LWIP_CALLBACK_API
+err_t tcp_recv_null(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err);
+#endif /* LWIP_CALLBACK_API */
+
+#if TCP_DEBUG || TCP_INPUT_DEBUG || TCP_OUTPUT_DEBUG
+void tcp_debug_print(struct tcp_hdr *tcphdr);
+void tcp_debug_print_flags(u8_t flags);
+void tcp_debug_print_state(enum tcp_state s);
+void tcp_debug_print_pcbs(void);
+s16_t tcp_pcbs_sane(void);
+#else
+# define tcp_debug_print(tcphdr)
+# define tcp_debug_print_flags(flags)
+# define tcp_debug_print_state(s)
+# define tcp_debug_print_pcbs()
+# define tcp_pcbs_sane() 1
+#endif /* TCP_DEBUG */
+
+/** External function (implemented in timers.c), called when TCP detects
+ * that a timer is needed (i.e. active- or time-wait-pcb found). */
+void tcp_timer_needed(void);
+
+void tcp_netif_ip_addr_changed(const ip_addr_t* old_addr, const ip_addr_t* new_addr);
+
+#if TCP_QUEUE_OOSEQ
+void tcp_free_ooseq(struct tcp_pcb *pcb);
+#endif
+
+#if LWIP_TCP_PCB_NUM_EXT_ARGS
+err_t tcp_ext_arg_invoke_callbacks_passive_open(struct tcp_pcb_listen *lpcb, struct tcp_pcb *cpcb);
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LWIP_TCP */
+
+#endif /* LWIP_HDR_TCP_PRIV_H */